SAFETY SAFETY SAFETY

In my recent assignment, I worked with potentially hazardous materials, underscoring the importance of handling such substances with care. Prior to utilizing any materials, it is critical to thoroughly read the safety data sheets provided for each one. These documents are vital as they detail the hazards associated with the materials, recommend safety equipment, and provide crucial instructions for emergencies. Additionally, understanding the properties of each product helps in safely managing and using them effectively.

The materials for this project were sourced from Poliformas Plásticas. Below is a detailed list of the products most commonly used, each accompanied by a brief description:

• RESIN PP-70x60: This is an unsaturated polyester resin with orthophthalic of pre-accelerated average reactivity. It features:
• Fast curing, even in thin sections.
• An appropriate percentage of solids for the intended application.
• Ease of use with fiberglass moisturizer.
• Consistent curing at various catalysis levels.
• Good acceptance of mineral charges.
• Development of good barcol hardness.


• RESIN PP-CRISTAL READY: A polyester resin known for its outstanding transparency and is used primarily for encapsulation. Its properties include:
• Medium reactivity, which offers more control over curing.
• Pressure Sensors: Useful for detecting force or weight; some can measure environmental pressure for altitude.
• Low shrinkage percentage to avoid issues with high thickness.
• Exceptional transparency and shine in the finished product.


• SILICON P-48: This is a vulcanizable silicone liquid rubber that sets at room temperature, used mainly for casting polyester resins, waxes, plasters, etc. It has:
• High viscosity.
• Room temperature vulcanization.
• Excellent resistance to temperatures up to 250 °C.


• SILICON DILUENT: A liquid used to dilute silicone rubber to the desired consistency, known for:
• Minimal viscosity variation with temperature.
• Non-toxicity and inertness.
• Excellent properties as electrical insulators.
• Resistance to high and low temperatures, UV radiation, chemicals, compression, and cutting efforts.


• CATALYST K-2000: Essential for curing unsaturated polyester resins and gel coats at room temperature, it includes:
• High active oxygen content (8.9 ± 0.1).
• Easy integration with resins and gel coats.
• Low water content.
• A clear, colorless liquid form.


• Silicon Rubber P-53 C/C: A high-performance, room temperature vulcanizing silicone rubber, ideal for mold making and encapsulation. It includes:
• Excellent mold release properties, allowing for easy demolding and maintenance of intricate details.
• High tear strength and superior flexibility, enabling the casting of complex shapes without compromising structural integrity.
• Good resistance to high temperatures, chemicals, and aging, ensuring durability and consistent performance in demanding applications.
• Specific formulation (C/C) that indicates tailored properties or curing characteristics to meet particular processing or performance requirements.

Most of these products require the mixing of two components: the active substance (A) and a catalyst (B). The catalyst initiates an exothermic chemical reaction that causes the resin or rubber to solidify. To ensure the correct proportions and mixing process, consulting the data sheets or speaking directly with the supplier is necessary to ascertain the precise quantities or percentages needed.

For safety and to ensure proper handling of these materials, accessing and understanding the data sheets is imperative. These guidelines not only protect the user but also ensure the integrity and success of the project.

You can see more info in this week's Group Assignment.

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Designing a Mold.

I recently embarked on an exciting venture to design a mold for a rubber duck, leveraging TinkerCad for the design process. My journey began at cults3d.com, where I discovered a charming rubber duck model crafted by an artist known as XCINNAY. Eager to transform this digital duck into a physical object, I exported the model into TinkerCad, where the real fun—and challenge—began.

In a somewhat "Inception"-esque twist, where the dream of creating something new embeds itself within layers of creation, I decided to split the duck model into two halves.

This wasn't just any split; it was to create a positive version of the duck, setting the stage to craft the negative mold. It felt like crafting a dream within a dream, where each layer brought its own reality closer to life.

A positive Rubber Duck mold:

A negative Rubber Duck mold:

To ensure the mold would be practical for casting, I added borders around each half of the mold design in TinkerCad.

Here is the 3D Model in SketchFab:

The final designs were then sent to an Elegoo 3D Printer 4 Max, which uses resin—a choice I made for its precision in capturing details. This resin is the Jayo 3D Photopolymer Resin

The process:

However, not all went according to plan. The initial excitement waddled into a challenge when the union of the two mold halves broke. It seems the duck wanted to swim before it could waddle!

Not one to back down from a challenge, I devised a new strategy and a new design. A new 'splitted' design!

I decided to print the base of the mold in resin, using the Elegoo 3D printer, and then crafted the borders with filament.

The process:

. This hybrid approach not only solved the issue of the breaking joints but also fit perfectly. Much to my delight, the final product quacked up to be better than I had anticipated.

However, I felt it was a little bit too small... so I decided to scale it up a bit more. After all, I wanted to have rubber ducks for my bath! (I don't even have a bathtub lol)

After that we had our positive molds!

This little adventure in mold-making turned out to be a fantastic blend of digital craftsmanship and problem-solving, proving that sometimes, when things don't go as planned, a little ingenuity (and a hybrid material strategy) can lead to results that really make a splash!

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Chemistry? Again?

Creating a negative mold is a meticulous and highly detailed process, especially when dealing with precise and small-scale models such as a rubber duck. For this particular project, I used a variety of materials and safety equipment to ensure both quality results and personal safety.

Materials Used:

• Vaseline: To ease the separation of the mold from the model.
• Catalyst K-2000: For curing the silicone rubber.
• Silicon Rubber P-53: The primary material for the mold.
• Resin PP-70x60: For the piece.
• Yellow Colorant: To tint the resin.
• Acetone: For cleaning and preparation.

Safety Equipment:

• Boots and Jeans: To protect from spills and splashes.
• Lab Coat: To keep clothing free of materials.
• Gas Mask: To avoid inhaling fumes.
• Safety Glasses: To protect the eyes from splashes.
• Rubber Gloves: To protect your hands from chemicals.

Process of Creating the Negative Mold:

1st Step: Preparing the Model

Before beginning the silicone casting, it's crucial to prepare the model properly. I started by generously applying Vaseline to the positive mold of the rubber duck. The Vaseline acts as a release agent, ensuring that once the silicone cures, it can be easily separated from the mold without sticking.

It’s important to remove any excess Vaseline, as too much can interfere with the mold’s detail capturing capabilities.

At the end, it should look something like this:

2nd Step: Mixing and Pouring the Silicone

The next step involved preparing the Silicon Rubber P-53. For every 100g of rubber, I added exactly 80 drops of Catalyst K-2000, adhering closely to the recommended ratio for optimal curing.

Thorough mixing is critical here to distribute the catalyst evenly throughout the silicone, preventing uncured patches and ensuring a consistent texture throughout the mold. During this mixing process, I took great care to eliminate any air bubbles, which can create imperfections in the mold.

After the silicone mixture was ready, I carefully poured it into the prepared mold. I used a slow, steady pour to avoid introducing new air bubbles and used a tool to gently push the silicone into every part of the mold, making sure it filled completely and captured every detail of the design.

From there I repeated this process for the other mold.

The silicone needed about four hours to cure fully so I placed a ventilator to help this process.

3rd Step: Extracting the Mold

During this time, it transformed from a viscous liquid to a solid, flexible rubber that retained the intricate details of the duck design perfectly. Once cured, the mold could be easily removed, thanks to the Vaseline applied earlier, revealing a high-fidelity negative imprint of the rubber duck, ready for casting duplicates.

Let's look more closely into how it turned out:

This process, while requiring precision and patience, is immensely rewarding. Not only does it allow for the creation of detailed replicas, but it also demonstrates the fascinating intersection of art and chemistry in the world of mold making.

Process of Creating the Piece:

The next step in my mold-making adventure involved working with resin, specifically Resin PP-70x60, to create a durable outer shell for my rubber duck mold. The process of preparing and casting resin requires precise measurement and careful handling to ensure the final product's integrity and safety.

DO NOT TRY THIS AT HOME WITHOUT THE PROPER GEAR AND IN AN OPEN AND VENTILATED SPACE

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Conclusion:

In conclusion, my journey from a confidently designed PCB to facing the trials of poor-quality solder has been both humbling and instructive. What began as a smooth path paved with clear intentions—to seamlessly integrate a temperature sensor with my Xiao module—became a testament to the unpredictability of the physical world and the craft of electronics. My ordeal with the solder taught me the irreplaceable value of quality materials and the importance of meticulousness in the soldering process.

he desoldering mesh, an unanticipated yet crucial tool, helped me salvage my components and, more importantly, served as a practical lesson in electronics repair. This experience, frustrating as it was, enriched my understanding of the assembly process and reaffirmed the notion that behind every successful project is a series of lessons learned through perseverance and adaptation.

As I look ahead, I am equipped not just with a better-soldered PCB but with a deeper appreciation for the art and science of electronics—a field where even the smallest details can make the largest difference.

The Files:

Below you can find the download links for all of the files from this week.

Main PCB files:

• {GamingPCB-F_Cu.svg}
• {GamingPCB-User_Drawings.svg}
• {GamingPCB mill traces}
• {GamingPCB mill outline}

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